Electric-arc lamp.



Patented Dec. I6, I902.

.1. A. HEANY. ELECTRIC ARC LAMP.

(Application filed Apr. 7, 1902.]

(,No Model.)

UNITED STATES PATENT OFFICE.

JOHN A. HEANY, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE TETER-HEANY DEVELOPING COMPANY, OF CHARLESTON, WEST VIR- GINIA, AND PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF WEST VIRGINIA.

ELECTRIC- SPECIFICATION forming part of Letters Patent No. 715,797, dated December 16, 1902.

Serial No. 101,634;- (No model.)

To whom it may concern.-

Be it known that I, JOHN A. I-IEANY, a citizen of the United States, residing at the city of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Electric-Arc Lamps, of which the following is a specification.

Myinvention has relation to that part of the [O regulating mechanism of an arc-lamp known as a dash-pot, and in such connection it relates to the construction and arrangement of the dash-pot.

Heretofore in electric-arc lamps dash-pots of two especial types or forms have been used namely, one type in which the dash-pot checks or brakes both the upward and downward movement of the feeding-clutch or regulating mechanism and another type in which the dash-pot checks or brakes only the sudden upward movement of said clutch or regulating mechanism. The dash-pot of my present invention is distinguishable from both of these types, as well as from all other types, in that there is provided means whereby only a sudden or abnormal upward movement of the clutch or regulating mechanism is checked and only the last portion of the sudden clownward movement of said clutch is checked or braked.

The principal object of my invention is to provide in an electric-arc lamp a dash-potof simple construction arranged so that its piston responds freely to a normal movement up 5 or down of the clutch or feeding mechanism for the carbons, and yet arranged so that a sudden upward movement of the piston is braked or checked within the cylinder of the dash-pot and a sudden downward movement of the piston is permitted for but a portion of its stroke in the cylinder, the remainder of the stroke being checked or braked by an interposed air-cushion.

The nature and scope of my invention will be more fully understood from the following description, taken in connection with the accompanying drawings, forming part hereof, in which- Figure 1 is a front elevational View, partly broken away, of a dash-pot embodying main features of my invention and of such parts of an electric-arc lamp as are necessary to illustrate the operation and arrangement of the dash-pot. view on the line a a of Fig. 1; and Fig. 3 is a transverse sectional view, enlarged, of the dash-pot.

Referring to the drawings, (t represents the solenoid-coil, a the framework upon which said coil is supported, and b the divided magnetic clutch responding to the action of the coil and adapted to feed the upper carbon 7).

The arrangement and construction of the foregoing parts, as well as of the central tube 17 in which the carbon b is fed, are substantially illustrated and described in Letters Patent No. 693,706, granted to me under date of February 18, 1902, and hence a detailed description of the same is not deemed necessary.

From the clutch 1) extends ashaft b forming a connection between the clutch l) and a dash-pot d. This dash-pot, forming the main 'featu re of my present invention, is constructed and arranged as follows: A lower shell or cylinder cl is fixed or otherwise secured to the framework of the lamp, and its upper open end 01 is of less external diameter than the external diameter of its lower closed end. Upon the upper end d telescopes or loosely slides an upper shell 6, and within the interior of the entire cylinder d slides a piston 6, connected by a stem 6 to the top or roof of the shell 6. In the periphery of the cylinder d is formed an air-inletf, into which a nipplef is inserted. In the nipple f is formed a valve seat and chamberffiin which is loosely placed a ball or check valvef The air-inletf is located some distance above the base of the cylinder cl and is adapted to be closed by the piston 6 during the latter part of the downstroke of said piston and to be uncovered and opened during the upward stroke and for a portion of the downstroke of the piston. On the roof of the upper shell 6 is formed a head 6 connected by the shaft 12 with the clutch b.

The operation of the dash-pot is as follows: If a slow upward or downward movement of the clutch 1) results from the influence of the Fig. 2 is a horizontal sectional solenoid-coil a, then the upper shell 6 slides slowly and easily upward or downward on the part d of cylinder d and the piston 6' slides easily upward. or downward in the cylinder 61. 5 During the slow upward movement of the piston e and shell 6 and as soon as the piston e clears the air-inlet fair enters the cylinder d below the piston e and air above the piston e is forced out between the upper shell 6 and the part (1 of the cylinder cl, upon which it slides. If there is a sudden or abnormal upward movement to the clutch b in response to the coil a, then the air above the piston 6 cannot escape with sufficient rapidity between the telescoping parts of the dash-pot, and hence an air-cushion is formed above the piston to assist in brakingor checking its upward movement. Again, the abnormal or rapid upward movement of the piston 6 leaves a vacuum in the base of the cylinder d, and the inrushing air through the air-inlet f serves to force the ball or check valve f upon its seat in the chamberf The vacuum thus preserved below the piston (2 serves also to retard or brake the upward movement of said piston e. During the slow downward movement of the piston e in the cylinder 61 the air below the piston is forced slowly out through the air-inlet f until the piston 6 passes the air-inlet f, when the air is confined within the cylinder below the piston and forms an air-cushion to brake or check even the slow downward movement of the piston. When the piston 6 drops or is forced violently downward in the cylinder (1, the check-valvef in the air-inlet fis forced away from its seat, but rests against the outer opening or way in the nipplef. Air in the cylinder d will then be confined some whatbelow the piston e to materially check the downward movement of said piston, and when the piston e closes the air-inletf then the complete confinement of the air below the piston 6 results in the formation of an air-cushion sufficiently strong to immediately stop the pistons movement. There is thus formed in the dash-pot of my invention during both a normal and a violent or abnormal downward movement of the piston a means for checking at the lowest part of the stroke said downward movement of the piston.

In the normal upward movement the piston is permitted to readily slide within its cylinder; but when an abnormal upward movementis given to the piston said movement is effectually checked or retarded.

Having thus described the nature and object of my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The combination,in an electric-arclamp, of a clutch for feeding one of the carbons, a solenoid controlling the reciprocation of said clutch, a dash-pot provided with a piston adapted to readily reciprocate during normal reciprocation of the clutch, means for checking or braking the abnormal upward movement of said piston and means for checking or braking the abnormal downward movement of the piston during the lower portion of the downward stroke of said piston.

2. In an electric-arc lamp, a dash-pot, comprising a cylinder, a piston adapted to normally reciprocate freely in said cylinder, means for checking or braking an abnormal movement of the piston in one direction in the cylinder and independent means for checking or braking the abnormal movement of the piston in the opposite direction in said cylinder.

3. In an electric-arc lamp, a dash-pot normally adapted to regulate the normal upward and downward movements of the feed mechanism for the lamp, combined with means for forming an air-cushion in said dash-pot during a portion of the downward movement of the feed mechanism.

4:. A dash-pot comprising a lower shell or cylinder, an upper shell telescoping or sliding freely over the exterior of the cylinder, a piston carried by the upper shell and traversing the interior of the cylinder, and a valvecontrolled air-inlet arranged in the periphery of the cylinder and above the base of said cylinder.

In testimony whereof I have hereunto set my signature in the presence of two subscribing witnesses.

JOHN. A. HEANY. Witnesses:

J. WALTER DOUGLASS, THOMAS M. SMITH. 

